To Sun Hill and The Bill, where a pristine new police station has just been unveiled. Amazingly, it has lasted two weeks without being set alight, petrol-bombed, or razed to the ground - by one of its own officers. Still, give it time. It is traditional in Sun Hill for them to torch the station annually so, given the levels of madness that layer the show, it can only be a matter of time before it is reduced to a cinder by a suicide bomber or an aggrieved resident of the Cockcroft estate with a weapon of mass destruction.

The Bill is that kind of show nowadays. Bonkers. Sociologists are divided on exactly which episode tipped it over the brink but my guess would be it was when Mark Fowler turned up as a PC Gabriel K*nt, started shagging his mother (Sgt June Ackland) and set up shop as the best sniper on television since The Day Of The Jackal. Dixon of Dock Green he ain't. The consensus is that The Bill stopped being a "serial drama" about a south London police station and turned into a soap for teenagers years ago - when all the sex-crazed bimbos and beefcakes started to push out the old-school cops with their gambling addictions, alcoholism and bad eating habits. Suddenly characters with names like Ken, Bob and, um, Jim were replaced by PCs called Honey, Suzie and Amber - not to mention the female officers.

In fact, what they've done with The Bill is a lot more complicated than that. Surprisingly gritty, seedy local crime combines with soft soap dalliances. Virtually each character - from the station cleaner to the superintendent - now has a more complicated personal life than Michael Jackson. In fact, working in Sun Hill is probably the most dangerous police station outside the barrios of Caracas - not because of the streets around it, but the people working inside it. Half the staff, as we know, are arsonists. Many are sleeping with or marrying murderers (DI Meadows, PC Kerry Young, now PC Honey Harmon) or, even worse than that, journalists. DS Ramani De Costa has or is a stalker.

But the current holder of the hotly-contested Most Personal Problems Award at Sun Hill is the man at the top - Superintendent Adam Okaro. Having been framed for possession of drugs not long ago, Okaro is currently doing a good (or not so good) impression of a cross between King Lear and Othello after his wife and family were killed in a car-crash. "You fell asleep and MY FAMILY IS DEAD!!" Okaro screamed at the woman involved after he had staged a home invasion and started terrorising her and her kids. So he's taking it badly then.

Several of the other officers have been connected to paedophilia in some way (DI Manson, DS Nixon, DC Terry Perkins) but then there are more paedophiles in Sun Hill than Bangkok. Last week's case was a reminder of how strong The Bill can be when, instead of messing around with the internecine love lives of its officers, it concentrates on an actual case - a novel idea, admittedly. Grim and unnerving to the point of being unwatchable, this was the 8pm equivalent of Kevin Bacon's The Woodsman or a Dennis Cooper novel in a case where DC Sim was determined to force a 12-year-old girl to admit she was being pimped by her mum and dad.

"She said she loved me." Maybe it would be preferable if The Bill stuck to canteen romances after all.

One day there may even be a storyline in a British cop show that doesn't involve paedophiles but not just yet. A six-part drama set in the north-west, Conviction, which starts tonight is - thankfully - closer in spirit and style to The Cops than to Merseybeat, not dissimilar to the excellent Julie Walters' drama Murder or Five's token good programme, Murder Prevention. A 12-year-old girl, "Little Angela", is dead - stabbed 38 times. The squad - Ray and his younger, wilder brother Chrissie, and old-school detective Joe - investigate. Joe takes the local paedophile for a Shield-style shakedown, telling him, "You did this and you're going to give it up to us or your life is going to be the worst hell that your pervy mind can imagine."

Conviction is gripping, bordering on brilliant, as bleak as its medical equivalent Bodies, lit up by typical gallows humour (Joe: "Old bloke goes to the doctor. Doctor says, 'You've got Alzheimer's and bronchitis.' Old bloke says, 'Thank God I haven't got bronchitis'"). Conviction, you can say with conviction, is a proper cop show and as such it's to be hoped the BBC stick by it a bit more than it did The Cops or Out Of The Blue. It is brilliantly cast - with strong, familiar faces never given enough of a chance to lead before - and nicely shot with enough slow motion, freeze-frames and flashbacks to be interesting without ever being as slick or superficial as Spooks or Hustle. As Ray says at the end of next Saturday's episode, "This case just keeps getting bigger, blacker..."

A staple of the American schedules, Cops has cops who are real but could equally be from an Elmore Leonard or Carl Hiaasen novel. Now in season 13, this month's action is set in such dead-end armpits of America as Jacksonville in Florida or Tacoma, Washington. Recent highlights followed the sheriff's department of Multnomah County in Portland giving the drug busts, car chases and domestic disturbances a look of Drugstore Cowboy. The squads in Cops are invariably some Sheriff Lonnie Hard Bastard ably assisted by Sgt John Dude and Detective Doug Serpico. Their lingo consists almost totally of brilliantly written dialogue. "We got tar heroin here gentlemen!" the sarge announced in one recent episode to whoops and hollers from the hard-drinking, ass-kicking good ol' boys standing round the trailer park in their Ray-Bans and shorts, watching. These were the sarge's fellow law-enforcement officers. Cops and criminals alike seem to base their hair around the covers of Hall & Oates records.

There is none of that nonsense with lawyers or police stations. "Who is the source for this cocaine?" they ask on the spot. "You just fell in a big hole pal," an undercover DLT lookalike snapped in the suspect's face when he tells them. "And it hasn't got much of a bottom in it." Cue no-nonsense frisking and delivering the suspect into the squad car ("Turn around, put your butt in first. Mind your head on the door." WHACK.) The raids and arrests like these have been parodied (not very well) by FX's Reno 911 for all the shouting and fat machismo that goes on. The chase scenes in Cops involving what Tony Soprano calls "the donut squad" are particularly funny. Frankly though seeing low-grade drug dealers grassing on their suppliers live on American television is still about as richly rewarding and entertaining as daytime television gets.